已知△ABC的三个内角A、B、C所对边分别为a、b、c，则“c=acosB”是“

下列哪项不属于保险人保证承保能力的主要途径？（）

A.保持风险分散

B.安排再保险

C.用特殊的承保技术和经验满足某些险种的承保要求

D.增加注册资本

请选用适当的试剂和分离装置除去下列物质中所含的杂质（括号内为杂质），将所选的试剂及装置的编号填入表中。

试剂：a．水   b．NaOH溶液  c．溴的CCl₄溶液  d．饱和Na₂CO₃溶液

e．新制CaO           f．饱和NaCl溶液

分离装置：

A．分液

B．过滤

C．洗气

D．蒸馏 F．盐析

They once seemed more at home on the busy streets of Asia like Delhi, Calcutta and Bangkok but cycle powered rickshaws (人力车) can now be seen taking people across town in many European cities. Many people believe that rickshaws are a good way of experiencing a city close-up, while also cutting down on traffic jams and pollution. In Berlin, one of the first cities to introduce this new model of transport, more than 200 bike-taxis go along at 15km per hour, past many tourist attractions and city parks.

“It is completely environmentally friendly; we have new models with an engine to help the driver up the hills but they use renewable energy.” said a spokesman for VELOTAXI, the leading rickshaw company which has carried a quarter of a million people this year.

While the city still has 7,000 motor-taxis, rickshaw company officials say their taxis’ green ideas, speed and safety make them more than just a tourist attraction. While now increasingly out of fashion in Delhi, Berlin people have eagerly accepted the new fleet since their launch in 1997.

“It’s better than a taxi, better than a bus, better than the train,” said ULF Lehman, 36, as he leapt out of a rickshaw near the world famous Brandenburg gate. “ It feels so free.”

“This is something out of the ordinary, you feel you are on holiday in Bangkok instead of Berlin,” said another traveler.

In Amsterdam, driver Peter Jancso said people like to be driven around in his bright yellow rickshaw and pretend to be a queen in a golden carriage. "I like my passengers to feel important," he said as he dropped off another passenger. Another visitor noted how cheap it was compared with a normal taxi.

Although increasingly popular in Europe, it is the opposite in India, where hand-pulled rickshaws are considered inhuman and a symbol of India's backward past.

Nearly 500 bike-rickshaws are running in London and are not required to pay the city's road tax but things may change as other taxi drivers complain of unfair treatment.

小题1:Where are rickshaws becoming more popular?

A．Delhi, Berlin, Paris.

B．Amsterdam, Bangkok, Delhi.

C．Athens, London, Berlin.

D．Berlin, Amsterdam, London.小题2:Why are rickshaws no longer as widely used in India as in the past?

A．They are a reminder of a bad period in India's history.

B．They have been banned because they are inefficient.

C．The streets of India are too crowded for them to move through easily.

D．Indians now prefer to travel by car because they are richer.小题3:What does the underlined sentence "This is something out of the ordinary, you feel you are on holiday in

Bangkok instead of Berlin" suggest?

A．The passenger didn't like taking a rickshaw as it reminded him of Bangkok.

B．The passenger enjoyed being on holiday in Berlin more than in Bangkok.

C．The passenger was impressed when taking a rickshaw and considered it unusual.

D．The passenger disapproved of rickshaws because they were not original to Berlin.小题4:What is the author's attitude towards rickshaws?

A．He gives no personal opinion.

B．He believes they will be of no use.

C．He thinks they will reduce pollution.

D．He thinks they are old-fashioned.

如图所示，一个装有空气的瓶子倒放在装有密度较大的红棕色二氧化氮气体的瓶子上，使两瓶口相对，两瓶口之间用一块玻璃板隔开，抽掉玻璃板后，可以观察到                       。这个现象说明              。

音速是飞行阻力的重要因素，音速受到的影响因素是（）。

A.空气中电波的传播速度

B.大气的温度

C.大气的密度

D.气压